Floribunda rose plant named ‘KORforst750’

ABSTRACT

‘KORforst750’ is a new and distinct variety of  Rosa hybrida  which is characterized by the combination of a bushy growth habit, a vigorous rate of growth, high resistance to common rose diseases, and panicles bearing three to six copper-yellow flowers. The new variety propagates successfully by stem cuttings and grafting and has shown to be uniform and stable in the resulting generations from asexual propagation.

Latin name of genus and species: The Latin name of the genus and species of the novel variety disclosed herein is Rosa hybrida.

Variety denomination: The inventive variety of Rosa hybrida disclosed herein has been given the variety denomination ‘KORforst750’.

STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR UNDER 37 C.F.R. 1.77(B)(6)

The first public disclosure of the claimed plant was made by the breeder in a press release on Jun. 29, 2015. ‘KORforst750’ was not publically available or sold prior to one year before the date of the instant application.

BACKGROUND OF THE INVENTION

Parentage: The Rosa hybrida variety ‘KORforst750’ is the result of a controlled cross-pollination breeding program carried out by the inventor in Klein Offenseth-Sparrieshoop, Germany. The objective of the said breeding program was to create a new and distinct rose plant with unique qualities, such as:

-   -   1. Uniform growth and flowering; and     -   2. Abundant, recurrent copper-yellow flowers; and     -   3. Attractive and abundant foliage; and     -   4. Resistance to diseases encountered in landscapes and gardens.

This combination of qualities is not present in prior rose cultivars known to the inventor. These objectives have been substantially achieved and in that distinguish ‘KORforst750’ from all other varieties known to the inventor.

‘KORforst750’ is a seedling selection which resulted from the controlled pollination of Rosa hybrida ‘INTERflocu’ (unpatented), the seed parent, and an unnamed Rosa hybrida seedling developed and owned by the same inventor, the pollen parent, during the summer of 2003. As part of a rose development program, Tim-Hermann Kordes germinated seeds from the aforementioned hybridization during the following winter and conducted evaluations and observations on the resulting seedlings in a controlled environment in Klein Offenseth-Sparrieshoop, Germany. The resulting seedlings exhibited distinctive physical and biological characteristics. The new rose plant was selected as a single plant in May of 2004 from the seedling beds due to its superior characteristics and asexually propagated for further evaluation. This new and distinctive rose variety was given the name ‘KORforst750’.

Asexual Reproduction: ‘KORforst750’ was first asexually propagated by bud grafting in July of 2004 at the inventor's nursery in Klein Offenseth-Sparrieshoop, Germany. Subsequently, ‘KORforst750’ has been successfully propagated by stem cuttings and bud grafting in Jackson County, Oreg. These initial and other subsequent propagations conducted in controlled environments demonstrate that ‘KORforst750’ reproduces true to type in successive generations of asexual reproduction.

SUMMARY OF THE INVENTION

The following characteristics have been repeatedly observed and represent the distinguishing characteristics of the new Rosa hybrida cultivar ‘KORforst750’. These traits, in combination, distinguish ‘KORforst750’ as a new and distinct cultivar.

-   -   1. Rosa hybrida ‘KORforst750’ exhibits a vigorous growth rate         and bushy habit; and     -   2. Rosa hybrida ‘KORforst750’ exhibits high resistance to rust,         black spot disease, Botrytis and powdery mildew; and     -   3. Rosa hybrida ‘KORforst750’ exhibits panicles of 3 to 6         copper-yellow flowers held upright to slightly pendant; and     -   4. Rosa hybrida ‘KORforst750’ exhibits double flowers of small         size for a floribunda rose.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying color drawing shows as true as is reasonably possible to obtain in color photographs of this type, the typical characteristics of the buds, sepals, reproductive organs, flowers, leaves, prickles, and stems of ‘KORforst750’, taken from a two year old plant.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed botanical description of a new and distinct variety of Rosa hybrida known as ‘KORforst750’, based upon observations made in October of 2015 from two year old, field-grown plants in Jackson County, Oreg. Those skilled in the art will appreciate that certain characteristics will vary with older or, conversely, with younger plants. ‘KORforst750’ has not been observed under all possible environmental conditions. Where dimensions, sizes, colors and other characteristics are given, it is to be understood that such characteristics are approximations or averages set forth as accurately as practicable. The phenotype of the variety may differ from the descriptions set forth herein with variations in environmental, climatic and cultural conditions. Color notations are based on The Royal Horticultural Society Colour Chart, The Royal Horticultural Society, London, 2001 edition except where common terms of color are used.

A botanical description of ‘KORforst750’ and comparisons with the parents and closest known comparator variety of Rosa hybrida are provided below.

-   General plant description:     -   -   Growth rate.—Vigorous.         -   Growth habit.—Bushy.         -   Mature dimensions.—120 cm tall and 70 cm wide, on average.         -   Cold hardiness.—Grown successfully in USDA Hardiness Zones             6.         -   Propagation.—Stem cuttings and bud grafting.         -   Disease resistance.—Highly resistant to powdery mildew             (Sphaerotheca pannosa), blackspot (Diplocarpon rosae), rust             (Phragmidium sp.) and Botrytis diseases under normal growing             conditions in Jackson County, Oreg. -   Root system: Moderately branched, fibrous root system with roots     evenly distributed throughout the soil profile, from shallow to     deep. -   Stems:     -   -   Stem color.—Young stems are Yellow-Green Group 146C; mature             stems are Yellow-Green Group 146D.         -   Anthocyanin intonations.—Intonations of Greyed-Red Group             182B are present on young stems.         -   Stem surface texture.—Both young and mature stems are             smooth.         -   Stem dimensions.—Typical mature stems are approximately 50             cm long and 5 mm in diameter.         -   Prickles.—Incidence — Typically 8 prickles per 10 cm of             stem, on average. Size — Average length is 10 mm long.             Immature prickle color — Greyed-Purple Group 184B. Mature             prickle color — Greyed-Orange Group 174D, with anthocyanin             intonations of Greyed-Purple Group 185B; senescing to Brown             Group 182C. Shape — Flat. Texture — Smooth. -   Leaves:     -   -   Arrangement.—Imparipinnate compound leaves; mature axillary             leaves consisting of 7 leaflets.         -   Attachment.—Petiolate.         -   Dimensions.—170 mm long and 110 mm wide.         -   Abundance.—Very abundant; approximately 150 leaves.         -   Stipules.—Size — 15 mm long and 5 mm wide. Stipule color —             Yellow-Green Group 146C. Anthocyanin intonations — Very             slight intonations of Greyed-Purple Group 184C are present             on the adaxial surface of the midrib. Stipitate glands — A             limited number of stipitate glands are present on the             margins and abaxial leaf surface. Margins — Serrated, with a             limited number of stipitate glands. Texture, adaxial             surfaces — Leathery. Texture, abaxial surfaces — Leathery.             Apex — Apiculate. Base — Flat; fused to the petiole.         -   Petiole.—Length — Average 10 mm. Diameter — Average 2.0 mm.             Petiole color, adaxial surface — Yellow-Green Group 146D.             Petiole color, abaxial surface — Yellow-Green Group 146C.             Anthocyanin intonations — None. Margins — Regularly             sequenced stipitate glands. Prickles — A single prickle is             present on the abaxial surface. Stipitate glands — A limited             number of stipitate glands are present on the margins and             the abaxial surface. Texture — Glabrous. Strength — Strong.         -   Rachis.—Length — Average 20 mm. Diameter — Average 2.0 mm.             Color — Yellow-Green Group 146D. Anthocyanin intonations —             Slight intonations of Greyed-Red Group 182B are present at             the point of leaf attachment on the adaxial surface and also             along the margins. Margins — With stipitate glands. Prickles             — A few small prickles on the abaxial surface. Stipitate             glands — An abundance of stipitate glands are present along             the margins and the abaxial surface. Texture — Glabrous.         -   Leaflets.—Dimensions — Average size of the terminal leaflet             is 65 mm long and 35 mm wide. Shape — Ovate. Apex — Acute.             Base — Obtuse. Margins — Serrated; slightly undulated.             Luster, texture and pubescence; adaxial surface —             Semi-glossy, smooth and glabrous. Luster, texture and             pubescence; abaxial surface — Matte, rugose and glabrous.             Juvenile foliage color, adaxial surface — Yellow-Green Group             147B. Juvenile foliage color, abaxial surface — Yellow-Green             Group 147B. Mature foliage color, adaxial surface —             Yellow-Green Group 147A. Mature foliage color, abaxial             surface — Yellow-Green Group 147C. Anthocyanin intonations —             Strong intonations of Greyed-Purple Group 187B are present             at the apices of juvenile foliage; weaker intonations of             Greyed-Purple Group 187B are present at the marginal zone             and midrib of both surfaces of the juvenile foliage.             Venation — Reticulate. Petiolule — Dimensions — 5 mm long             and 1 mm in diameter. Petiolule color, adaxial surface —             Yellow-Green Group 146B. Petiolule color, abaxial surface —             Yellow-Green Group 146D. Anthocyanin intonations — None             present. Prickles — None present. Texture, adaxial and             abaxial surfaces — Leathery. Margins — With stipitate glands             on both the adaxial and abaxial surfaces. -   Inflorescence:     -   -   Inflorescence type.—Panicles which bear 3 to 6 flower buds.             Flowers are held upright to slightly pendant.         -   Blooming habit.—Recurrent; floriferous.         -   Size.—15 cm tall and 14 cm wide, on average.         -   Peduncle.—Length — 60 to 100 mm average length. Diameter —             3.0 to 4.0 mm average diameter. Color — Yellow-Green Group             146C. Anthocyanin intonations — Slight intonations of             Greyed-Purple Group 183C are present on a portion of the             peduncle. Strength — Strong. Surface — Smooth with stipitate             glands and numerous prickles; prickle color is Greyed-Purple             Group 184B. -   Flowering laterals: Present below the initiation of inflorescence.     Generally 1 to 2 flowering laterals are present, with 1 flower per     flowering shoot. -   Bud:     -   -   Bud form.—Short; pointed ovoid.         -   Size.—Upon opening, 30 mm in length from base of receptacle             to distal end of bud and 23 mm diameter at its widest point.         -   Texture.—Smooth.         -   Color, as sepals first unfold.—Orange-Red Group 32C.         -   Color when one-quarter open, inner side.—Marginal zone —             Orange Group 24C. Middle zone — Yellow Group 11D. Basal zone             — Yellow Group 13B.         -   Color when one-quarter open, outer side.—Marginal zone — Red             Group 37B. Middle zone — Red Group 37B, with center striped             Yellow-White Group 158D. Basal zone — Yellow-Orange Group             14C, with a petal spot, Red Group 45C. -   Flower:     -   -   Pedicel.—Length — 35 to 60 mm average length. Diameter — 2.0             to 3.0 mm average diameter. Color — Yellow-Green Group 146C.             Anthocyanin intonations — Very strong intonations of             Greyed-Purple Group 183C. Strength — Strong to somewhat             strong. Surface — Glabrous with an abundance of stipitate             glands.         -   Calyx.—General — Comprised of five polysepalous sepals, with             weak to moderate foliaceous appendages present on two of the             five sepals. Diameter of calyx — 80 mm, at anthesis.         -   Sepals.—Color, upper surface — Yellow-Green Group 146D.             Color, lower surface — Yellow-Green Group 146B. Anthocyanin             intonations — Strong intonations of Greyed-Purple Group 185B             on the lower surface, and Greyed-Purple Group 185D on the             upper surface. Size — 25 to 35 mm long and 7 to 8 mm wide,             on average. Apex — Apiculate to cirrose; typically 1 to 2             sepals are cirrose. Base — Flat at union with receptacle.             Quantity — Five.         -   Upper surface.—Lightly pubescent.         -   Lower surface.—Stipitate glands present.         -   Margins.—Pubescent with abundant stipitate glands.         -   Corolla.—Habit — Double. Density of petals — Medium. General             shape of corolla — Irregular round. Profile of corolla when             viewed from the side — Upon opening, upper portion — Flat.             Upon opening, lower portion — Concave. Open flower, upper             portion — Flattened convex. Open flower, lower portion —             Flattened convex. Dimensions — Small size for a floribunda             rose. When open, the average flower diameter is 70 mm and             the average flower height is 40 mm. Fragrance — Light, sweet             fragrance. Duration — On the plant for 3 to 4 days. Senesced             petals drop away cleanly. Petals — Petal count — Exhibits             double flowers with an average of 34 petals under normal             conditions. Petal reflex — Petals are slightly reflexed.             Timing of petal reflex — Simultaneous. Petal margin —             Entire. Petal shape — Obovate. Apex — Obtuse. Base —             Cuneate. Dimensions — 40 mm long and 35 mm wide. Texture,             inner surface — Smooth. Texture, outer surface — Smooth.             Petal color, upon opening — Outermost petals, inner surface             — Marginal zone — Orange Group 24D. Middle zone — Orange             Group 24D. Basal zone — Yellow Group 13B. Outermost petals,             outer surface — Marginal zone — Red Group 38B. Middle zone —             Orange-Red Group 32D. Basal zone — Yellow Group 9C.             Innermost petals, inner surface — Marginal zone —             Yellow-Orange Group 23B. Middle zone — Distinct stripe,             Yellow Group 6B. Basal zone — Yellow Group 6B. Innermost             petals, outer surface — Marginal zone — Red Group 41D.             Middle zone — Distinct stripe, Yellow Group 6B. Basal zone —             Yellow Group 6B. Basal petal spots, upon opening — Outermost             petals — Color, inner surface — No distinct petal spot.             Color, outer surface — Yellow Group 9C. Dimensions — 3 mm             wide and 3 mm tall. Innermost petals — Color, inner surface             — Yellow Group 6B. Color, outer surface — Yellow Group 6B.             Dimensions — 3 mm wide and 3 mm tall. Petal color, after             opening — Outermost petals, inner surface — Marginal zone —             Yellow-Orange Group 20D. Middle zone — Yellow-Orange Group             20D. Basal zone — Yellow-Orange Group 20D. Outermost petals,             outer surface — Marginal zone — Red Group 36D. Middle zone —             Red Group 36D. Basal zone — Yellow Group 2B. Innermost             petals, inner surface — Marginal zone — Yellow-Orange Group             20D. Middle zone — Yellow-Orange Group 20D. Basal zone —             Yellow Group 5B. Innermost petals, outer surface — Marginal             zone — Red Group 38D. Middle zone — Red Group 38D. Basal             zone — Yellow Group 2B. Basal petal spots, after opening —             Outermost petals — Color, inner surface — Yellow Group 8A.             Color, outer surface — Yellow Group 5B. Dimensions — 2 mm             wide and 2 mm tall. Innermost petals — Color, inner surface             — Yellow Group 5B. Color, outer surface — Yellow Group 2B.             Dimensions — 2 mm wide and 2 mm tall. General Tonality — On             open flower, Orange Group 24D. No change in general tonality             at the end of the fourth day; thereafter the general             tonality is Orange Group 27D. Petaloids — Quantity — 3             petaloids per flower, on average. Dimensions — Approximately             2 to 5 mm long and 2 to 4 mm wide. Color, inner surface —             Marginal zone — Yellow-Orange Group 20D. Middle zone —             Yellow-Orange Group 20D. Basal zone — Yellow Group 12D.             Color, outer surface — Marginal zone — Red Group 38B. Middle             zone — Red Group 38B. Basal zone — Yellow Group 4B. Margins             — Very irregular; entire to undulated to indented. Shape —             Oval to obovate to spatulate. Apex — Obtuse. Base —             Attenuate to obtuse. Texture, inner and outer surfaces —             Smooth. -   Reproductive organs:     -   -   Stamens.—Quantity — Approximately 68, on average, and             regularly arranged around the styles. Anthers — Shape —             Reniform. Dimensions — 3.0 mm long and 0.5 mm wide, on             average. Color — Greyed-Orange Group 163A. Pollen — Present;             scarce. Color is Greyed-Orange Group 165B. Filaments — Color             — Yellow Gimp 12A. Length — 5 mm.         -   Pistils.—Quantity — Average; approximately 50. Stigmas —             Size — 1 mm. Location — Slightly inferior in position to             anthers. Color — Greyed-Yellow Group 162A. Styles — Length —             Approximately 4 mm long. Color — Yellow-Green 145C.         -   Ovary.—Dimensions — 5 mm long and 4 mm in diameter. Color —             White Group 155A.         -   Receptacle.—Shape — Funnel-shaped. Dimensions —             Approximately 7 mm high and 7 mm wide. Color — Yellow-Green             Group 146C, with very strong intonations of Greyed-Purple             Group 187B present over approximately 90 percent of the             receptacle. Texture — Smooth, with a few fine white hairs,             colored nearest to White Group 155A. -   Hips and seed formation: Not observed.

COMPARISONS WITH THE PARENTS

The new rose plant may be distinguished from its seed parent, Rosa hybrida ‘INTERflocu’, by the following combination of characteristics:

-   -   1. ‘KORforst750’ exhibits copper-yellow flowers, whereas         ‘INTERflocu’ exhibits yellow flowers with pink edges.     -   2. ‘KORforst750’ exhibits high disease resistance, whereas         ‘INTERflocu’ exhibits average disease resistance.     -   3. ‘KORforst750’ exhibits a small size flower for a floribunda         rose, whereas ‘INTERflocu’ exhibits a large flower.

The new rose plant may be distinguished from its pollen parent, a Rosa hybrida breeding line developed by the inventor, by the following combination of characteristics:

-   -   1. ‘KORforst750’ exhibits copper-yellow flowers, whereas the         pollen parent exhibits yellow flowers.     -   2. ‘KORforst750’ exhibits a double petal count, whereas the         pollen parent exhibits a semi-double petal count.     -   3. ‘KORforst750’ exhibits a bushy growth habit, whereas the         pollen parent exhibits an upright habit.

COMPARISON WITH THE MOST SIMILAR ROSA CULTIVAR KNOWN TO THE INVENTOR

For a comparison, several physical characteristics of the Rosa hybrida variety ‘KORmelaus’, a rose variety from the same inventor which is described and illustrated in U.S. Pat. No. 26,116, are compared to ‘KORforst750’ in Chart 1.

CHART 1 Characteristic ‘KORforst750’ ‘KORmelaus’ General tonality of the Orange Group 24D. Yellow-Orange flower, at anthesis. Group 29A. Petal count. 34 or more. 23 to 30. Anthocyanin Strong intonations Weaker intonations intonations. on the juvenile on the juvenile leaflets, leaflet leaflets, leaflet midribs, and rachis; midribs, and rachis; strong intonations on weaker intonations juvenile stems. on juvenile stems. 

That which is claimed is:
 1. A new and distinct variety of rose plant named ‘KORforst750’, as described and illustrated herein. 